This was a lovely opportunity to develop leadership and mentorship skills outside a school setting as a child, and I remember enjoying teaching several friends to read, but I resented being made to be an unpaid staff member in school. In school, I knew that other children were learning, but that it was at the expense of *my* foregone opportunity to learn. Contrary to your concern that it causes arrogance, being a peer mentor made me feel ignored and unappreciated because my needs weren't being met.
I hope the contrast between those two scenarios was helpful.
